1. Field of the Invention
The present invention relates to an electroluminescence apparatus applicable to display devices, light-emitting sources, or printer heads of electrophotographic printers, and a method for driving it. More particularly, the invention relates to an apparatus using organic electroluminescence members suitable for full-color display of large screen, and a method for driving it.
2. Related Background Art
The known organic electroluminescence members are, for example, those disclosed in Japanese Laid-open Patent Applications No. 6-256759, No. 6-136360, No. 6-188074, No. 6-192654, and No. 8-41452.
It is also known that these organic electroluminescence members are driven by thin film transistors, for example, as described in Japanese Laid-open Patent Application No. 8-241048.
For driving the organic electroluminescence members by the thin film transistors, an organic electroluminescence member had to be mounted per drain electrode pad of thin film transistor, however. Particularly, in the case of the full-color display, the electroluminescence members of three kinds for electroluminescence emission of the three primary colors, blue, green, and red, had to be patterned on a thin film transistor substrate. Since the thin film transistor surface had greater unevenness than thin films of the electroluminescence members, it was difficult to pattern the thin films of electroluminescence members in high definition and high density. A further problem was that productivity was low, because the two types of functional devices, the transistors and electroluminescence members, were concentrated on the thin film transistor substrate.
The organic electroluminescence members had a further problem that long-term application of dc voltage thereto shortened continuous emission time. Particularly, when they were driven by the thin film transistors disclosed in Japanese Laid-open Patent Application No. 8-241048 etc., there arose a problem that the dc voltage was continuously applied to the organic electroluminescence members, so as to promote deterioration of the organic electroluminescence members.